Manganese Ferrite Containing Glass-Crystalline Materials—Phase Composition, Microstructure and Magnetic Properties

The preparation of new magnetic materials is important because of their potential application in various electronic components. In the present work, the synthesis of glass-crystalline materials in the system Na2O-MnO-SiO2-Fe2O3 prepared by applying melt-quenching is reported. The phase composition as studied by X-ray diffraction and Raman spectroscopy reveals the precipitation of monophase MnxFe3−xO4 based solid solutions. The microstructure is studied by scanning electron and optical microscopy and shows bulk crystallization and the presence of polygon-shaped as well as of dendritic crystals, depending on the iron oxide concentration and used raw materials. Mössbauer spectra show that in the amorphous matrix the Fe ions are mainly present as Fe3+ in tetrahedral coordination and as Fe3+ in a solid solution with the composition MnxFe3−xO4. The simultaneous presence of MnFe2O4 (jacobsite) and a Mn-containing solid solution based on Fe3O4 (magnetite) is suggested. The room temperature magnetic properties were studied by vibrating sample magnetometer and reveal ferrimagnetic properties for all investigated glass-crystalline materials.